No killing! Except parademons, of course ...

I've noticed this. Ever since the days of the original DC Animated Universe.
The following was only the most recent reminder, and has got me wondering now if heroes used lethal sanction against these poor guys in the actual COMICS when they first appeared:

^^^Always an interesting subject.

This link talks about the DCAU and comics in general.

I don't think the Justice League was sparring any Thanagarians either in the final battle from the Starcrossed arc, from the Justice League animated series.

🙁

Riv, there's no link.

Back to topic, that was Wonder Woman, here's one Karen Starr ...

Hmm.

I discovered something unfortunate about tinypic.com in posting that just now.

Well, let me try this; maybe I can correct it:

http://tinypic.com/r/ofd9ux/9

http://tvtropes.org/pmwiki/pmwiki.php/Main/WhatMeasureIsANonHuman

Here you go.